Add Migration Entities in LINQ

Introduction

 

Today, in this article let's play around with one of the interesting and most useful concepts in LINQ.

 

Question: What is adding migration entities?

 

In simple terms "It enables creation of a database structure and performs database migrations for adding a new property or updating the database structure".

 

Step 1: Create a new web application


 Output1.jpg


 

 Step 2: The complete code of Student.cs looks like this:
 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace AddMigrationsApp

{

    public class Student

    {

        public int Id

        {

            get;

            set;

        }

        public string FirstName

        {

            get;

            set;

        }

        public string LastName

        {

            get;

            set;

        }

        public int Age

        {

            get;

            set;

        }

        public string Location

        {

            get;

            set;

        }

    }

}

 

Step 3: The complete code of StudentContext.cs looks like this:
 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Data.Entity;

namespace AddMigrationsApp

{

    public class StudentContext : DbContext

    {

        public DbSet<Student> Students

        {

            get;

            set;

        }

    }

}


Step 4: The complete code of WebForm1.aspx looks like this:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="AddMigrationsApp.WebForm1" %>

 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head id="Head1" runat="server">

    <title></title>

</head>

<body>

    <form id="form1" runat="server">

    <div>

        <center>

            <table>

                <tr>

                    <td>

                        <asp:Label ID="Label1" runat="server" Text="Insert Data Add Migration" Font-Bold="true"></asp:Label>

                    </td>

                </tr>

            </table>

            <br />

            <br />

            <table>

                <tr>

                    <td>

                        <asp:Label ID="Label2" runat="server" Text="Please Enter FirstName: " ForeColor="Brown"

                            Font-Bold="true" Font-Italic="true"></asp:Label>

                    </td>

                    <td>

                        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

                    </td>

                </tr>

                <tr>

                    <td>

                        <asp:Label ID="Label3" runat="server" Text="Please Enter LastName: " ForeColor="Brown"

                            Font-Bold="true" Font-Italic="true"></asp:Label>

                    </td>

                    <td>

                        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>

                    </td>

                </tr>

                <tr>

                    <td>

                        <asp:Label ID="Label4" runat="server" Text="Please Enter Age: " ForeColor="Brown"

                            Font-Bold="true" Font-Italic="true"></asp:Label>

                    </td>

                    <td>

                        <asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>

                    </td>

                </tr>

                <tr>

                    <td colspan="2" align="center">

                        <asp:Button ID="Button1" runat="server" Text="Insert Data" OnClick="Button1_Click"

                            BackColor="Orange" Font-Bold="true" /><br />

                        <br />

                    </td>

                </tr>

            </table>

            <br />

            <br />

            <table>

                <tr>

                    <td colspan="3">

                        <asp:Label ID="Label5" runat="server" Font-Bold="true"></asp:Label>

                    </td>

                </tr>

            </table>

        </center>

    </div>

    </form>

</body>

</html>

 

Step 5: The complete code of WebForm1.aspx.cs looks like this:

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

namespace AddMigrationsApp

{

    public partial class WebForm1 : System.Web.UI.Page

    {

        protected void Page_Load(object sender, EventArgs e)

        {

        }

        protected void Button1_Click(object sender, EventArgs e)

        {

            if

                (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text) || string.IsNullOrEmpty(TextBox3.Text))

            {

                Label5.Text = "Please Enter Some Values";

                Label5.ForeColor = System.Drawing.Color.Red;

            }

            else

            {

                var addStudent = new Student

                {

                    FirstName = TextBox1.Text,

                    LastName = TextBox2.Text,

                    Age = Convert.ToInt32(TextBox3.Text)

                };

                objContext.Students.Add(addStudent);

                objContext.SaveChanges();

                Label5.Text = "Data Successfully Inserted";

                Label5.ForeColor = System.Drawing.Color.Green; TextBox1.Text = string.Empty;

                TextBox2.Text = string.Empty; TextBox3.Text = string.Empty;

            }

        }

        #region Instance MembersStudentContext objContext = new StudentContext();

        #endregion

    }

}

 

Step 6: The output of the application looks like this:
 

Output2.png
 

Step 7: The inserted data output of the application looks like this:
 

Output3.png
 

Step 8: The database created output of the application looks like this:
 

Output4.png

 

Step 9: The enabling migrations output of the application looks like this:
 

Output5.png
 

Step 10: The adding new property migrations output of the application looks like this:
 

Output6.png

 

Step 11: The update database migrations output of the application looks like this:
 

Output7.png
 

Step 12: The database updated output of the application looks like this:
 

Output8.png
 

I hope this article was useful for you.